Increased Constitutive Chitinase Activity in Transformed Trichoderma harzianum

Haran, Shoshan; Schickler, Hedva; Pe’er, Sara; Logemann, Susanne; Oppenheim, Amos B.; Chet, I.

doi:10.1006/bcon.1993.1016

Cited by 33 publications

(18 citation statements)

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“…Furthermore, transformation of exogenous or homologous genes from Trichoderma also greatly improves the efficiency of biocontrol fungi (Deng et al 2007; Haran et al 1993; Limón et al 1999; Margolles-Clark et al 1996; Yang et al 2011). However, few effective C. rosea strains have been genetically engineered, and the genetic manipulation of antifungal chitinase genes from mycoparasite C. rosea is largely unexplored.…”

Section: Introductionmentioning

confidence: 99%

Transformation of the endochitinase gene Chi67-1 in Clonostachys rosea 67-1 increases its biocontrol activity against Sclerotinia sclerotiorum

et al. 2017

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Clonostachys rosea is a promising biocontrol fungus active against various plant fungal pathogens. In this study, the endochitinase-encoding gene Chi67-1, the expression of which is sharply upregulated in C. rosea 67-1 when induced by sclerotia, was transformed into the original isolate by protoplast transformation, and transformants were screened against Sclerotinia rot of soybean. The transformation efficiency was approximately 50 transformants per 1 × 107 protoplasts, and 68 stably heritable recombinants were assayed. The parasitic rates of 32.4% of the tested strains increased by more than 50% compared to 43.3% of the wild type strain in 16 h, and the Rc4-4 transformant showed a parasitic rate of 100% in 16 h. The control efficiencies of the selected efficient transformants to soybean Sclerotinia stem rot were evaluated in pots in the greenhouse, and the results revealed that Rc4-4 achieved the highest efficiency of 81.4%, which was 31.7% and 28.7% higher than the control achieved by the wide type and the pesticide carbendazim, respectively. Furthermore, the expression level of Chi67-1 was 107-fold higher in Rc4-4 than in the wild type, and accordingly, the chitinase activity of the recombinant increased by 140%. The results lay a foundation for the development of efficient genetically engineered strains of C. rosea.

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Section: Introductionmentioning

confidence: 99%

Transformation of the endochitinase gene Chi67-1 in Clonostachys rosea 67-1 increases its biocontrol activity against Sclerotinia sclerotiorum

et al. 2017

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“…Chitin, the unbranched homopolymer of N-acetylglucosamine connected together by b-1, 4 bonds, is a structural component of cell walls in most fungi (Saksirirat and Hoppe 1991;Mathivana et al 1997;Kim et al 2001). Through the degradation of the chitin polymer in the cell walls of fungal pathogens, chitinase (EC 3.2.1.14) plays a vital role in the biological control of many plant diseases (Haran et al 1993). It affects fungal growth through lysis of the cell walls (Kunz et al 1992), hyphal tips, and germ tubes (Gunarantna and Balasubramanian 1994).…”

Section: Introductionmentioning

confidence: 99%

Antifungal chitinases from Bacillus pumilus SG2: preliminary report

Ghasemi

Ahmadian

Jelodar

et al. 2010

World J Microbiol Biotechnol

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A halotolerant bacterium capable of chitinase production was previously isolated from saline soils of Gavkhooni marsh, Iran. The strain was identified as Bacillus pumilus strain SG2. This strain secretes two chitinases into the medium in response to the presence of chitin in the medium. The two chitinases, ChiS and ChiL, were active on both polymeric as well as oligosaccharide substrates. In this study, these two extracellular chitinases were purified from the supernatant of the Bacillus culture by ammonium sulfate precipitation. The optimum pH and temperature for both of these chitinases were pH 6 and 37°C, respectively. According to the conserved domain analysis, ChiS and ChiL were categorized in family 18 of the glycosylhydrolases. Three essential conserved amino acid residues in in ChiL were found within the active site. Antifungal activities of the two purified chitinases were assessed on Rhizoctonia solani, Verticillium sp., Nigrospora sp., Stemphyllium botryosum and Bipolaris sp. demonstrating inhibition of all the tested strains. However, these chitinases did not inhibit cell wall formation of the non-chitin-containing fungi (oomycetes) Phytophthora citricola and Phytophthora capsici. This is the first investigation demonstrating antifungal activity of chitinases purified from B. pumilus SG2.

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“…Among these, chitinase (EC 3.2.1.14) plays a vital role in the biological control of many plant diseases by degrading the chitin polymer in the cell walls of fungal pathogens (Haran et al, 1993). It affects fungal growth through the lysis of cell walls (Kunz et al, 1992), hypal tips, and germ tubes (Gunarantna and Balasubramanian 1994).…”

Section: Introductionmentioning

confidence: 99%